


Our Promise, Our Future

by SiesFics



Category: Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: Alpha Sylvain Jose Gautier, Alpha/Beta/Omega Dynamics, Implied Mpreg, Knotting, Love Confessions, M/M, Omega Felix Hugo Fraldarius, Praise, soft
Language: English
Status: Completed
Published: 2020-06-02
Updated: 2020-06-02
Packaged: 2021-03-03 04:55:14
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings, No Archive Warnings Apply
Chapters: 1
Words: 3,987
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/24499024
Author URL: https://archiveofourown.org/users/SiesFics/pseuds/SiesFics
Summary: Felix has his first heat in years. Sylvain is there to help him out and feelings are exchanged.
Relationships: Felix Hugo Fraldarius/Sylvain Jose Gautier
Comments: 2
Kudos: 140





	Our Promise, Our Future

**Author's Note:**

> Write a short abo I said, it'll be fine I said. It's not short, feelings got in the way. Hope you enjoy! Not edited! apologies for mistakes.

Felix feels the heat in his skin, prickling through him like fire licking at dead grass. It was never ideal to go into heat in the middle of a war, but Felix had run out of suppressants long ago and Mercedes could only do so much with her magic. He’d managed to avoid heats for the last five years but his luck had run dry, as had any patience for people. He’d left the meeting almost immediately, feeling that familiar warmth and turning on his heels. He was the only omega to have sprouted among their group because of course he was. The war council was made up primarily of alphas and betas. A few of their additions to the fight, Linhardt, Dorothea, and Hilda were all omegas but they didn’t attend the councils, so during those hours long meetings, Felix was truly the only one among them. It wasn’t normally something he thought about, but right now it was the only thing on his mind. It was why he’d left, and why he had locked himself away in his old room. He’d had such easy access to suppressants before that this was the first real heat he’d had since presenting and he was already sick of it. 

He ripped his coat off and wrestled with his thigh high boots before throwing himself haphazardly into bed. He was prepared to suffer for the next few days, writhing in his own sweat and cum, humiliated at how much his body craved a knot. 

A knock on his door had him tensing, although hearing Mercedes’ voice calmed him. As a beta, she posed no threat to him, she had no reaction to his scent. “Felix, I heard you left rather abruptly from the war council...I’m sorry my magic can’t do more.” 

“It’s fine...you can’t be expected to fix everything,” he breathed out, tearing off his shirt and tossing it into the ever growing pile. 

“May I come in?” He grunted in response and made sure he was safely under the blankets before the door opened. He heard Mercedes footsteps, the sound of a pitcher on the desk. “I’m leaving water for you, make sure you drink. I’ll come by three times a day to bring more water and food for you.” 

“Thank you,” Felix mumbled, practically hearing her smile. She left and for a few minutes he just laid there, breathing in his own scent which had begun to permeate the room. Another knock and he wondered what she forgot, sitting up to face her, but rather than Mercedes he was greeted with the redheaded lancer he had been stupidly and hopelessly in love with. 

“Sylvain! Get out of here!” He snarled, throwing the closest thing he could reach at Sylvain’s stupid face. When he had been a kid he stuck to Sylvain like glue, always nursing a crush on the older boy. Once Sylvain had presented, his father had been eager to pair him with a budding omega in order to secure heirs and further the Gautier bloodline. Felix had given up any idea of being with Sylvain after he presented himself, not ever wanting his oldest and dearest friend to think he was using him. But despite his attempts, Felix had never stopped loving Sylvain. If anything it had grown stronger and more intense during their time at Garreg Mach, and even more so upon meeting up again five years later. 

“You left the meeting so quickly, but not fast enough that we didn’t all know why.” Sylvain’s golden eyes had darkened some, the longer he stood in this room, surrounded by the most intoxicating smell. He’d also spent years nursing his love for Felix, but never wanting to seem like he was only after the other for a claim. His love for Felix went beyond alphas and omegas, to a point where he actually thought Felix might be the one. Felix’s scent was warm like honey and cinnamon, with a dash of freshly sprinkled snow. 

“If you know why then why are you here?” Felix glared at him, pulling the blanket over him, as if that were going to help any. “You need to leave Sylvain, I won’t be another one of your toys!” He wouldn’t allow himself to be just another omega to Sylvain, he couldn’t. 

Sylvain’s eyes narrowed and he let out an exasperated sigh. “I suppose I deserve that sort of rumor, with how I was when we were younger…” He grabbed a chair and sat down, far enough away from Felix that he wouldn’t pounce, though that was getting harder the longer he sat steeped in the scent of a fertile omega. Not just any omega either, Felix. “Fe, I don’t know what you heard when we were younger, but I never marked a single person I was with. I fooled around with a lot of girls, that much is true, but I’ve never bonded to anyone because none of them were you.” 

Felix’s breath caught in his throat and he dared to look at Sylvain. “What are you talking about?” 

“You know how when we were young, Glenn told us all we’d know when we found our mate because there would be a certain feeling? He said it was like being drawn to someone by rope. I remember thinking back then how I couldn’t imagine my mate being anyone but you.” 

“Why are you talking about this?” Felix curled his fingers into the blanket, glaring at the floor. “If that’s true, then why didn’t you say so?” 

“I was scared. Scared to lose you, Fe. If I had been wrong, then what would you have thought of me? I was afraid that you’d think I was only after you for what you are. I could have done a lot of things differently, and I can’t take back what’s happened. But Fe, I want to offer myself to you now. I want to help you through this heat and prove myself worthy to be your mate.” Sylvain had never felt worthy of anything in his life. He had never shown his true self to anyone but Felix and it took him years to realize why that was. His childhood dream of being with Felix forever wasn’t a dream anymore, it was something he could vocalize. Felix was the only person who ever told him the trust 100% of the time. He was the one person that Sylvain knew he could trust without worry, and he had spent so long consumed with his own guilt he had never asked how Felix felt. 

Felix’s heart was hammering in his chest, his eyes were ringing and he couldn’t believe what he was hearing. Sylvain Jose Gautier was telling him he wanted to be his mate, and not in that joking way Felix knew Sylvain for. “No bonding,” Felix murmured. “I want to save that for when we end the war.” If they both survived this, then he’d let himself be happy. Until then, all he could do was enjoy the moment.  
Sylvain smiled. Not one of the false smiles he gave to most everyone, but a genuine smile he saved for moments like these. “No bonding, got it. So what you’re saying is that when we both come out of this alive, we can mark one another?” Felix’s flustered grumble made Sylvain’s heart feel so full. He couldn’t be happier in this moment, having Felix admit his feelings in the most Felix way possible, strict and to the point. 

“Shut up,” Felix groaned. “You’re insufferable…” The longer Sylvain had been in the room, the more potent his scent became to Felix. It was rich, pine needles and fire, a musk that Felix had scented for years, but now was close enough to taste. It was filling his head and making him weak. Between his legs he could feel his cock hard against him, and slick pooling into the sheets below. He hated what heat did to him, made him feel so weak. 

Sylvain could smell it all. He could smell Felix’s arousal, his slick, and it was mouth watering. Sylvain stood up, taking slow steps toward the bed. He sat on the edge, wanting so badly to touch, but forcing himself back. “Fe, do you want me to leave?” He asked, quiet, desperate. He didn’t want to leave, he loathed the idea of it, but he would not go against what Felix wanted.

“No I don’t want you to fucking leave.” Felix growled, grabbing Sylvain by that stupid green undershit of his and pulling him flush against his naked chest, skin on fire. “Make it stop, I’m burning.” And he whined. Felix fucking whined and it was the most embarassing sound he had ever made, but at least it was only in front of Sylvain. “I love you you stupid idiot, can’t you see that?” 

Sylvain’s breath caught in his throat when Felix pulled him close, his scent overpowering Sylvain’s senses. He groaned at Felix’s words, his plea, his confession. “I love you too Fe, I always have,” he whispered. All the years he’d spent with countless, nameless women had only been to drown out his feelings for Felix back when he’d thought them impossible. He used to laugh at himself, he used to think he didn’t deserve a happy ending. And yet with Felix it felt so much more like a reality. “Can I…?” His hands were shaking, waiting for the okay, even though it already seemed pretty likely. He just couldn’t risk it with Felix, he wouldn’t fuck this up. 

“Goddess yes Sylvain,” Felix groaned. He could scarcely think, his mind was a mess, muddled from his heat and overworked from having confessed his long suppressed feelings. 

Sylvain couldn’t move fast enough, arm wrapping around Felix’s waist and shifting their bodies until Sylvain was lying on the bead and on top of him. The weight of the omega was a welcome one, one he’d dreamed about. He had to see Felix like this, exposed for him, bare for the taking. “Fe, you’re perfect…” Felix’s body was as toned as it always had been, arm and stomach muscles hard from years of training. His legs were thin and petite, his strong suit being a sword, not a horse. He’d cut his hair some time ago, but it was still long enough that Sylvain could reach up and toy with. Felix was so refined, so beautiful in Sylvain’s eyes. He reached out to touch, running his fingers down Felix’s damp skin, squeezing his thighs. Felix shifted impatiently above him, causing Sylvain to groan from the contact. “Fe, holy fuck.” Sylvain pulled Felix closer, reaching behind and spreading his cheek with one hand, the other pressing delicately against Felix’s aching hole. It was positively dripping wet, spilling eagerly down pale thighs. Sylvain felt like he was going to go feral with how incredible Felix smelled. 

“It’s so humiliating,” Felix grumbled. 

“Humiliating? You were made for me Fe...feel how wet you are?” Sylvain purred as he slid a finger inside, no resistance, only an eager omega hole begging for more. “You’re so warm and tight, I can’t wait to knot you.” He smirked at the positively whorish whimper that Felix let out. Sylvain was lucky, he knew that he was the only one who had ever heard this, or been able to touch Felix. And if this all turned out as he hoped, he’d be the only one to do this period. 

Felix wiggled his hips, hating how easily he moaned and whimpered for Sylvian once the other had a single finger inside of him. But he’d never been with someone for his heat before, had never allowed himself to be vulnerable in front of anyone. But Sylvain made it easy, because he knew Sylvain would never do anything to hurt him. Felix pressed his face into Sylvain’s neck, teeth aching to bite into flesh and seal their bond. But he’d made them both promise to wait until the war was won. So he busied himself with nipping at the skin, worrying it in his teeth and moaning every time Sylvain slid another finger in. 

Sylvain felt that ache too, wanting so badly to seize Felix by the neck and bond them together. Felix was occupied with his neck, causing Sylvain to stutter in his movements when he bit just a little harder, sending jolts of pleasure straight to his dick. “Goddess...Fe, c’mere…” He pulled his fingers out and moved them again, situating Felix on the bed. He groaned when Felix, unprompted, spread his legs to fit Sylvain between. “You’re gonna kill me,” he whispered. It was perfect the way Felix was, pliant and eager for him. 

“Sylvain, what are you doing?” Felix’s breath was catching the longer he was being made to wait. His hole was aching for an alpha, for Sylvain, and all the other was doing was staring at him. He blushed furiously as he watched Sylvain lift his slick soaked fingers and press them into his mouth. Sylvain’s moan made Felix want to die. “Don’t you dare say anything about the taste!”

“Why not? Felix, you taste divine, so warm...I could drink you,” he cooed. “Let me get a taste of you, turn around, on your knees.” He said it with a growl, one so primal and alpha he knew Felix could not refuse. 

Felix felt something in him, something that told him to listen. He hated this inherent omega desire to listen, but with Sylvain he supposed it wasn’t the worst. Pushing himself up, Felix flipped over, pessing his knees into the bed and supporting himself with his arms. The purr that breathed its way into his ear had him shaking. 

“Such a good omega for me. Fe, I’m gonna make you so full of me,” Sylvain hummed, delighted in the full body shiver from the swordsman. “Let yourself give into the pleasure, enjoy your heat for the first time. I’ll be here always, so relax,” he urged. Sylvain settled down, spreading Felix’s cheeks to get to his puckered, leaking hole. The amount that Felix produced showed how fertile he was, and Sylvain fully intended to take advantage of that, in due time. For now, thanks to the suppressants, it would take years for Felix to be able to produce a child, but when that time came, Sylvain would be there. 

Sylvain leaned in, wasting no time in slipping his tongue inside of Felix, moaning at the indescribably euphoric taste. It was like nothing he’d ever had, it was perfect, and wholly Felix. 

Felix’s eyes snapped open when Sylvain entered him, tongue pressing deep, so deep that Felix felt his legs shake. “Syl...I want to cum,” he whimpered, shaking his head, tempted to touch himself, but withholding. 

Sylvain licked his way around Felix’s walls before withdrawing his tongue and licking his lips. “You’re so good for me Fe, let’s get you taken care of…” Felix would be able to cum multiple times throughout a single session of his heat, so it was best, in Sylvains view, if they spread them out so as not to overwhelm him. He moved from behind Felix, to under him, one hand holding the quivering omega’s hip, the other moving behind to press two fingers inside of him. Felix jolted, moaning, and Sylvain took the opportunity to open his mouth and swallow Felix down. 

Felix pressed his face into the pillow and sobbed, his whole body jerking into the fingers, then back into Sylvain’s mouth. “S-Sylvain!” Felix was stammering, gripping for anything and everything, rocking his hips and fucking Sylvain’s mouth. His orgasm quickly mounted and ran him over like a horse. Felix shouted, so loudly the pillow hardly covered it up. He came hard, hips stuttering, all the while Sylvain’s mouth was still wrapped around him, sucking him, tongue running delicately over the head, and fingers buried deep. 

Sylvain swallowed all of Felix, savoring the taste of him. He pulled off, licking the head clean before letting it go. “Such a good boy, Fe...but I know you’re still aching, aren’t you? Why don’t you tell me what you want? What you need.” 

Felix was boneless, collapsed on the bed, taking mouthfuls of air. He let Sylvain shift them, turning him onto his back, the redhead now positioned above him. He was smiling down at him, smug bastard. “You know what I want,” he growled. His cock was already hard again, his hole was empty, and nothing could fix it except a knot. That’s how it always was and he’d have suffered alone if not for this insufferable man. 

“Perhaps. But I really want to hear you say it. I want to know what you need from me.” Sylvain coaxed him, smiling all the while. He knew this part would be hard for Felix, but he needed to hear it. To know what Felix didn’t want just any alpha, he wanted Sylvain.  
“Ugh. Fine! You’re so stupid,” he huffed, crossing his arms over his chest. “I want you to fuck me. I want your stupid fat knot inside of me and I want us to win this war so we can bond.” Might as well say it all again, what we wanted now and in the future. He shouted in surprise when Sylvain flopped down on top of him, arms wrapping underneath him and pulling him close. “What are you doing?” 

“I’m just...I’m happy Fe. I’ve wanted to be bonded to you my whole life, but never thought I was good enough for you. Hearing you say it so much just makes it all the more real. We’ll survive, I promise.” Sylvain pressed his face into Felix’s dark hair, breathing him in, aching to move lower and claim him. It was going to be an aching desire in him until the day came when they could solidify their love for one another in a way that would declare it to the world. Right now wasn’t the time to be sappy though, Sylvain had to take care of Felix and he wouldn’t disappoint. Pushing himself up, he reached over and dug out some oil from the drawer, thankful Felix had prepared this much. He poured it onto his hand and cock, stroking himself to coat every inch in the cool oil. He had a feeling Felix was wet enough that he didn’t need the oil, but Sylvain didn’t want to take any chances. “Okay Fe, you ready?” He murmured, smiling at the grumpy whine he got in response. 

“Of course I am. I’ve been ready! Please Syl, goddess…” Felix was feeling so desperate that he was begging. His eyes fluttered closed as Sylvain drew close, breathing against his neck, teeth grazing the sensitive skin. A hand grabbed his hip, thumb stroking the bone gently, urging him to spread himself a little wider. He bit back a whimper, anticipation filling his belly as Sylvain guided himself to him, head pressing against his hole and slipping in with little resistance. Felix felt his whole body jolt, finally getting what it had wanted for the past few hours, and what he had denied it for longer than a decade. 

Sylvain slid in a few more inches but had to stop, both hands gripping Felix’s hips, breathing hard through his nose. He knew Felix would be tight but he worried he would blow his load before he even bottomed out. “Felix, you’re so fucking tight,” he breathed, groaning and pushing himself in some more, moving inch by inch until he felt Felix’s skin against his. Sylvain let his head fall back, moaning at just the feeling of Felix around him. 

“Sylvain, move!” Felix growled, pressing himself down, fucking himself helplessly on Sylvain’s cock. 

“Sorry, you just...you’re perfect Fe.” Sylvain pulled out, waiting for Felix’s whine before slamming his hips forward, the cry he punched out of the omega was such a sweet sound. Any restraint he had once had, any worries, had melted away the moment Felix begged him for more. He’d never focus so intently on his partner before, never cared about them beyond getting his own pleasure taken care of. But Felix wasn’t just some omega he was using, he was someone Sylvain had cherished since he’d met him, bundled up in his mother’s arms. He’d known his love was true when they had been small and Felix had helped him out of the well, crying like he always did as a child. Their promise to one another had extended far into their futures, and Sylvain was determined more than ever to keep it. 

Felix curled his fingers into the sheets, pulling them frantically as Sylvain thrust into him. His legs wrapped around Sylvain’s waist, locking them together, moaning from the sheer pleasure of letting himself enjoy this, feeling every punctuating thrust, each roll of Sylvain’s perfectly sculpted hips. Felix wiggled underneath Sylvain, uncurling his hands in order to bring them up and thread them through rust colored hair. He brushed back the hair sticking to Sylvain’s forehead, the cavalier so handsome like this, letting his true self show. Felix shuddered at the feeling of Sylvain’s knot, beginning to form at the base, reminding him what he was doing, and who he was doing this with. “Inside, please, fuck, cum inside of me,” he begged. 

Sylvain’s golden eyes narrowed, darkened even at the sight and sound of Felix begging him. “You want me to fill you up Fe? I’m going to make you so fucking full of my seed, and years from now I’m going to breed you until you’re full of our kin,” he growled. What he wanted more than anything was to love Felix, and to love a family with him. For now, he was happy with just loving Felix. His hips snapped forward, rutting like an animal into Felix’s body, his own orgasm mounting. He didn’t let himself knot omegas, had never wanted to wind up getting someone pregnant he had no interest in, but Felix was his mate, and he couldn’t help himself. Every thrust began to slow, his knot catching on Felix’s rim, causing the younger man to wail. Sylvain took a moment to commit this to memory, Felix begging and crying for him, writhing like a whore. “Fuck Fe, not gonna last,” he groaned, jerking his hips forward one last time. His knot slipped inside of Felix and expanded, locking them together. He moaned, low and loud, gripping Felix’s hips and rutting into him through his release. 

Felix had never been with anyone before and couldn’t have imagined it would have felt quite like this. His mind went blank when Sylvain came, when his knot caught and locked inside of him. Felix knew he screamed, but he couldn’t remember doing it, couldn’t remember Sylvain’s hand wrapping around him and ripping a second, mind shattering orgasm through him. When he opened his eyes again, Sylvain was lying beside him, their limbs tangled up and Sylvain very much still cumming loads inside of him. Felix felt so full of the redhead, his hand instinctively touching his stomach, grunting at the foolish idea running through his mind. 

“Was it good?” Sylvain asked quietly, combing a hand through Felix’s dark hair. He smiled at the wrinkled up look he got. 

“It was fine…” Now that he had his mind back, Felix refused to acknowledge any of what had happened that was potentially humiliating. 

“I’m so happy you approve.” Sylvain laughed and pulled Felix close to his chest, tilting his chin and kissing him. He’d never felt so happy before, so hopeful for a future. 

Felix relaxed into their embrace, letting his eyes flutter close and enjoying the feelings that ran like lightning through his veins. He loved this man. This foolish man. Both of them now fought not only for their king, but for each other and their future.


End file.
